Magnesium Fertilizer Increased Growth, Rhizome Yield, and Essential Oil Content of Ginger (Zingiber officinale) in Organic Field

Ginger (Zingiber officinale) is the main biopharmaceutical export commodity of Indonesia. However, its productivity and quality are low because it is not cultivated using optimal techniques. This study aimed to examine the effect of magnesium (Mg) fertilizer on the growth, rhizome yield, and essential oil content of two ginger varieties in the organic field. The two factors tested were the rate of Mg fertilizer application (0, 50, 100, and 150 kg MgOha-1) and the variety of ginger (elephant ginger [Zingiber officinale var. officinarum] and red ginger [Zingiber officinale var. rubrum]). The variables measured were plant height, number of leaves, number of tillers, rhizome weight, and essential oil content. Mg fertilizer application rate and ginger variety significantly affected growth, yield, and essential oil content. No interaction effects were found between the two factors. Mg fertilizer applied at 150 kg MgOha-1 resulted in the highest rhizome yield and essential oil content, with an increase of 21.74% and 15.38%, respectively, compared to the control (0 kg MgOha-1). The yield of elephant ginger was 29.41% higher than that of red ginger, whereas the essential oil content of the red ginger was 16.67% higher than that of the elephant ginger

PAKET WISATA EDUKASI SUBAK UPAYA MENJAGA KEBERLANJUTAN POTENSI PERTANIAN DAN PARIWISATA BERBASIS BUDAYA DI BALI

Tourism and agriculture are leading sectors of development in Bali Province. Before Bali’s economy relies heavily on tourism sector, agriculture was a major driver of economic growth. However, with so many challenges of land adjustment and use, and the increase tendency of agricultural land conversion into non-agricultural purpose, the growth of the agricultural sector gradually decreased. Declining of agriculture domain might cause a challenge for Bali because agriculture is not just an activity of land cultivation, but it has related more as spirit or the essential substances of Balinese cultural identity. One of the agricultural universal icons is the Subak system, which has named as world cultural heritage by UNESCO in 2012. Thus, to ensure the sustainability of the agricultural and tourism in Bali, the effort to combine both fields through development of Subak educational tourism becomes relevant. This idea is based on the perspectives that agricultural and tourism areas are interrelated systems. Tourism in Bali is counting on how Bali can preserve its natural and cultural attractions, this include the agrarian culture and lifestyle. The emergence of knowledge-based society, that encourage travellers to be actively involved and participate to fulfill their desire of learning and understanding others culture, has greatly contributed to development of this special interest tourism. Study indicated that Subak educational tourism can be applied toward sustainability as it incorporated the aspect of natural and socio-cultural conservation and could offer economic benefits for the well-being of the local community

Residual Effect of Compost on Ethanol Production of Sweet Soghum [Sorghum bicolor (L.) Moench] Varieties and Soil Organic Carbon at Dryland Farming Area in Bali, Indonesia

Increasing ethanol production of sweet sorghum have been receiving much attention under this era of finding new sustainable sources of bioenergy. Compost did not significantly affect biomass and ethanol production of four sweet sorghum varieties planted in 2012, therefore the objective of the 2013 experiment was to study the residual effect of compost applied in 2012 on ethanol production of sweet sorghum [Sorghum bicolor (L.) Moench] varieties and on soil organic carbon. The experiment was designed as randomized complete block with three replications and two treatment factors (rate of compost residues and sweet sorghum varieties) were in factorial arrangement. The compost residues were in the rates of 0, 10, 20, 30 t ha-1 (similar to rates applied in 2012), while the varieties were Super Sugar, Sugar Graze, SG-1A and Local Belu NTT. Super Sugar and Local Belu were the varieties used in 2012. The experiment was conducted from June until November 2013 at dryland farming area of Jimbaran, Badung Bali, Indonesia.  Results of the experiment showed that residual effect of compost and the interaction effect between the two factors were not significant on ethanol content, sugar yield, juice production, ethanol production ha-1 and on soil organic carbon. Those parameters were only affected significantly (P<0.05) by variety. The highest ethanol production (1314.87 l ha-1 ) was given by SG-1A, which was not significantly different from those of Super Sugar and Sugar Graze varieties (920.41 l ha-1 and 1257.92 l ha-1). The highest stem ethanol content (91.31%) was produced by SG-1A, and the lowest (90.40%) was given by Local Belu variety. Low (<1.0%) soil organic carbon content was found in whole experiment. In conclusion, that high ethanol production could not be expected from residual effect of compost alone especially under low soil fertility. Keywords: Residual effect, Compost, Ethanol, Sweet sorghum, Soil organic carbo

Biomass of Various Tropical Legume Cover Crops Increase Soil Quality of Dryland Soils in Badung Bali, Indonesia

Two field experiments were conducted to study the effects of tropical legume cover crops on soil quality in dryland farming areas at Angantaka village, Badung regency, Bali Province of Indonesia from June to November 2013.  In the first experiment, three tropical legume cover crops (LCC) (Centrosema pubescens L.(Cp), Mucuna pruriens L.(Mp) and Pueraria javanica L. (Pj)) and one control (without LCC) were arranged in a randomized complete block design with four replicates.  Variables measured were the quality of LCC biomass, C-absorbed and fixed-N by LCC.  The LCCs were harvested after three months, which were then incorporated into the soil according to the treatments set for the second experiment.  Design for the second experiment was a Split-plot with four replicates, where residues (biomass) of three LCC (results of the first experiment) were assigned as the main plot and four times of biomas incorporation (0,10, 20 and 30 days) as the subplot.  Results showed that Pj was the best LCC crop among others (Cp and Mp) due to its highest quality. Pj also had the highest absorbed-carbon (58.50 t ha-1), fixed-N (490.21 kg ha-1), biomass FW and DW (304.83 and 116.99 t ha-1) among LCC species. The  treatment of Pj with 30 days biomass incorporation significantly improved the soil quality as indicated by the highest soil moisture content (40.25%) and porosity (79.90%), organic-C (1.95%), total N (0.09%), available-P (15.71 mg kg-1), exchangeable-K (2.07 mg kg-1) and soil respiration (63.94 meC-CO2 kg-1day-1 ). Keywords: Biomass, Tropical legume cover crop, Soil quality

Soil Organic Carbon, Labile Carbon and Organic Carbon Storage under Organic and Conventional Systems of Chinese Cabbage in Baturiti, Bali Indonesia

Soil organic carbon storage (SOCS) is one of indicator for soil quality.  It requires several years to be able to detect the SOCS and the impact on crop yields.  A research was conducted to study soil organic carbon (SOC), labile carbon (SLC), SOCS and the yields of Chinese cabbage (Brassica chinensis L.) under organic and conventional farming systems.  The location was at the area of vegetable farming in Baturiti village, Tabanan regency, Bali province, Indonesia, between 08032’93”SL and 115017’64”EL, 975 m above sea level. Soil samples were taken from the land of organic system after one, three and five years of application, and from the conventional system accordingly in the neighboring area.  Variables of SOC, SLC, SOCS, total nitrogen, soil respiration and bulk density were measured.  The yields of Chinese cabbage were obtained from the last five years of farmer records. Results of this study indicated that SOC, SLC, SOCS, total nitrogen and soil respiration, but not soil bulk density, were significantly (P<0.05) higher under organic than under its conventional counterpart after five years application of organic system. The SOCS increased 3.37 Mg C ha-1 annualy under organic compared to that under conventional system. The SOC, SLC and soil microbial respiration significantly 68.6%, 49.01% and 38.5% higher respectively under organic farming system after five years, but soil nitrogen did not increase. The organic system was highly correlated (r= 0.836**, r=0.846**) with levels of SOC and SLC respectively. During the first three years the yield of Chinese cabbage was lower under organic but after five years the yields (25.78 t ha-1) was not significantly different from that in conventional system. This explains that significant yield increases in organic farming system could only be expected after five years of application. Keywords: Soil organic carbon, soil organic carbon storage, labile carbon, organic farming system, conventional farming system, Chinese cabbage (Brassica chinensis L.)

Adaptation, Biomass and Ethanol Yields of Sweet Sorghum (Sorghum bicolor (L.) Moench) Varieties at Dryland Farming Areas of Jimbaran Bali, Indonesia

Decreasing the availability of fossil energy sources in Indonesia, demand that an alternative and renewable source of energy is to be found. Sweet sorghum is a possible candidate for a cheap and renewable source of energy. An experiment was conducted to study the adaptation of sweet sorghum varieties and to find out the optimum rate of organic manure for high biomass and ethanol yields in dryland areas at Jimbaran, Badung, Bali. The experiment was a two factor experiment in a randomized complete block design with three replications. The first factor was four sorghum varieties, three varieties  originated from Japan viz. Kotobun sorgo (FS501), Big sugar sorgo (FS902), Super sugar (KCS105) and Local Belu originated from East Lesser Sunda islands, Indonesia, and the second factor was four rates of organic manure of 0, 10, 20, 30 t ha-1. The four varieties adapted well on dryland areas at Jimbaran, Badung, Bali,  butFS902, KCS105 and Lokal Belu had better growth compared to FS501. The variety of KCS105 resulted in significantly (P<0.05) highest total biomass fresh and dry weight of 28.2 and 9.7 t ha-1 , respectively, stem sugar yield of 2.6 t ha-1and stem ethanol yield of 6493.3 l ha-1, which was 63.3% higher than that of Local Belu eventhough their ethanol content were similar.  No significant effect was found in the rates of organic manures and the interaction between the two factors on biomass, sugar and ethanol yields. The optimum rate of manure for highest biomass, sugar and ethanol yields was not  found in this experiment. It was concluded that the four sorghum varieties were well adapted and KC105 produced highest biomass and ethanol in dryland areas at Jimbaran, Badung, Bali. Keywords: Adaptation, Biomass, Ethanol, Sweet sorghum (Sorghum bicolor (L.) Moench).